pyramid-opentracing 0.1.4

Installation

Run the following command:

$ pip install pyramid_opentracing

Setting up Tracing for All Requests

In order to implement tracing in your system (for all the requests), add the following lines of code to your site’s Configuration section to enable the tracing tween:

# OpenTracing settings

# if not included, defaults to False
config.add_attributes({'ot.trace_all': True})

# defaults to []
# only valid if 'opentracing_trace_all' == True
config.add_attributes({'ot.traced_attributes': ['host', 'method', ...]})

# a module-level function that returns the operation name for a request object.
# defaults to the matched route name or request's method if none.
config.add_attributes({'ot.operation_name_func': 'my_main_module.get_operation_name_func'})

# One valid underlying OpenTracing implementation as
# one either one of these two values:

# 1. A tracer object itself.
config.add_attributes({'ot.base_tracer': ...})

# 2. Or a module-level function that returns a tracer object,
#    receiving the settings, such as: create_tracer(**settings)
config.add_attributes({'ot.base_tracer_func', 'my_main_module.utils.create_tracer')

# enable the tween
config.include('pyramid_opentracing')

Alternatively, you can configure the tween through an INI file:

[app:myapp]
ot.trace_all = true
ot.operation_name_func = my_main_module.get_operation_name_func
ot.traced_attributes = host
                      method
ot.base_tracer_func = my_main_module.utils.get_tracer
pyramid.includes = pyramid_opentracing

Once the tween has been included, an instance of PyramidTracer will be exist in registry.settings[‘ot.tracer’] for any further reference.

Note: Valid request attributes to trace are listed [here](http://docs.pylonsproject.org/projects/pyramid/en/latest/api/request.html#pyramid.request.Request). When you trace an attribute, this means that created spans will have tags with the attribute name and the request’s value.

Tracing Individual Requests

If you don’t want to trace all requests to your site, you can use function decorators to trace individual view functions. This can be done by managing a globally unique PyramidTracer object yourself, and then adding the following lines of code to any file that has view functions:

# get_tracer() should return a globally-unique PyramidTracer object.
from my_tracer_mod import get_tracer

tracer = get_tracer()

# put the decorator after @view_config, if used
@tracer.trace(optional_args)
def some_view_func(request):
    ... #do some stuff

This tracing method doesn’t use the tween, so there’s no need to include that one.

The optional arguments allow for tracing of request attributes. For example, if you want to trace metadata, you could pass in @tracer.trace(‘headers’) and request.headers would be set as a tag on all spans for this view function.

Examples

Here is an tween example of a Pyramid application that uses the Pyramid tween to log all requests:

Here is an client server example of an application that acts as both a client and server, with a manually managed tracer (you will need to install the waitress module).

Other examples are included under the examples directrory.

Further Information

If you’re interested in learning more about the OpenTracing standard, please visit opentracing.io or join the mailing list. If you would like to implement OpenTracing in your project and need help, feel free to send us a note at community@opentracing.io.